1. Field of the Invention
This invention relates to an improved method and improved apparatus for autoradiography.
2. Description of the Prior Art
As used herein, the word "specimen" shall mean human, animal, plant and bacterial cells, tissues or other samples obtained from a human, animal or plant and which are to be analyzed for medical or research purposes.
It has been known in many fields to provide specimens on slides, such as glass microscope slides, for study purposes. It is also known to label such specimens with various radioactive materials. The presence of radioactive binding to specimen can be determined. Under known practices, the specimen bearing slides are individually, manually engaged on the frosted end and each is individually dipped into a photographic emulsion and subsequently placed in a drying rack. Not only is this a time-consuming process when a large number of slides are to be processed, but also wet hands of the individual performing the test causes the fingers to lose their sensitivity for detecting the frosted ends of the slide. As a result, frequently undesired dipping of the frosted end into the emulsion occurs. Similarly, individual placement of the dipped slides into the drying rack is a time consuming procedure which often results in inadvertent sticking of slides to each other or slides being dropped or the emulsion surface being damaged through undesired contact with fingers, other slides, rack portions or other objects. Further, if slides are overdried while in the drying rack, it becomes difficult, if not impossible, to remove them from the rack.
Under known practices, after the slides have dried in the drying rack they are stored in light-proof boxes. This requires individual removal of the slides from the drying rack in an environment of total darkness and placing the slide vertically in narrow slots in the light-proof boxes. The boxes are then taped around the edges or wrapped with aluminum foil to resist light leakage. The sealed box containing the specimen bearing, emulsion coated slides is then introduced into a regrigerator for exposure. Typically, the sealed box is introduced into a refrigerator having a temperature of about 4.degree. C. and, depending on the type of study being performed, is left there for about one day to six months. During this period in the sealed box, the radioactive material emits energy, such as alpha or beta particles or gamma rays, which reduces silver bromide in the photographic emulsion to metallic silver. The exposure is generally done at 4.degree. C. in order to minimize undesired background. Also, the box is sealed during exposure to avoid undesired exposure of the emulsion to light which would tend to ruin the slide.
After the desired exposure, each slide must be removed from the black or light-proof box and placed vertically in glass trays for development. This practice requires not only extensive individual handling of the slides, but also that the slides not be permitted to touch each other. It is generally not possible to fill such a tray while avoiding slides being stuck together and, as a result, efficient placement of slides in such a tray generally occurs with respect to less than the full capacity of the tray thereby resulting in waste of the worker's time as well as developer, stopper and fixing solutions.
As a result of the above-described problems, it is customary in many types of tests to prepare and process several slides of the same specimen in order to improve the chances of obtaining an acceptable result.
There remains, therefore, a substantial need for improved means of processing such specimen-bearing slides.